1. Field of the Invention
The present invention relates an image pickup apparatus equipped with a zoom lens having a reflecting member that deflects the optical path to make the thickness of the apparatus smaller.
2. Description of the Related Art
Zoom lenses in which a reflecting member that deflects the optical path is provided in the optical path of the zoom lens to reduce the thickness of image pickup apparatuses (in particular digital cameras) have been known.
In particular, there is a known image pickup apparatus equipped with a zoom lens in which a reflecting member is provided in the first lens unit closest to the object side among the lens units in the zoom lens and the zoom lens is fixed relative to the body of the apparatus to eliminate extension of the zoom lens from the apparatus body. Such elimination of the extension of the zoom lens from the apparatus body enables improvement in the resistance of the image pickup apparatus against dust, water and impacts.
Recently, needs for zoom lenses having a high zoom ratio and a wide angle of view have been growing in addition to needs for slimming of image pickup apparatuses.
Japanese Patent Application Laid-Open No. 2009-236973 discloses a zoom lens that responds to such needs.
The zoom lens disclosed in Japanese Patent Application Laid-Open No. 2009-236973 includes, in order from the object side, a first lens unit having a positive refracting power, a second lens unit having a negative refracting power, an aperture stop, a third lens unit having a positive refracting power, a fourth lens unit having a negative refracting power, and a fifth lens unit having a positive refracting power, wherein a reflecting member (specifically, a rectangular prism) is provided in the first lens unit, and the second lens unit, the aperture stop, the third lens unit, and the fifth lens unit are moved independently from each other during zooming from the wide angle end to the telephoto end. This zoom lens has a high zoom of approximately 10. In the zoom lens disclosed in Japanese Patent Application Laid-Open No. 2009-236973, the second lens unit is moved by a large amount to provide an adequate magnification change, achieving a high zoom ratio. In order for the first lens unit to have an appropriately high positive refracting power, it is configured to include, in order from the object side, a negative lens, the reflecting member (rectangular prism) and two positive lenses disposed on its image side. Thus, the positive refracting powers are distributed to the two lenses to reduce aberrations.